<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>29.Promise-catch方法</title>
</head>
<body>
    <script>
        // catch 用来指定promise失败的一个回调
        const p = new Promise((resolve,reject) => {
            setTimeout(()=>{
                //设置 p 对象的状态为失败，并设置失败的值
                reject("出错了！");
            },1000)
        })

       /*  p.then(function(value){},function(reason){
            console.error(reason);
        }) */

        p.catch(function(reason){
            console.log(reason);
        })
    </script>
</body>
</html> 